I am close to hitting level 3 and plan on being a Chainlock.  However, at 4th level I could skip boosting CHA to 20 and take a feat, and I'm thinking of scooping Ritual Caster [Bard].  For reference, I'm playing a half-elf with a Fiend Patron that has the background of noble.  I see people mention being a Tomelock and then taking Find Familiar to get a light version of what a Chainlock can do.  Any thoughts of reversing that and taking the cool familiar and just using a feat for some ritual spells?

Bard no, Wizard yes.  Intelligence casting ability or not, Wizard has ninety percent of the useful ritual spells, and not a single one of them actually cares about your casting modifier.

As for how effective Chainlock w/Ritual Caster is versus Tomelock w/Find Familiar?  Matter of emphasis.  The Tomelock doesn't give up a feat to get its familiar the way the Chainlock does, but by the same token the Tomelock does give up an Invocation.  Whether you value feats or Invocations more is on you.  Chainlock w/Ritual Caster keys off of character level, so if you multiclass later you still get higher-level rituals.  Not so for Book of Ancient Secrets.  Obviously Chainlock doesn't get extra cantrips or the potential ability not to sleep, but they do get improved healing and all the goodness of Chainlock.

I'd say go for it, especially if your party is light on utility casters.  You'd be surprised just how often ritual spells can save a LOT of headache.

Everything that Yurei says.  Definitely Ritual Caster: Wizard over Bard should you go that route.  I'm presently playing a Celestial Tomelock, and I am pretty happy with the choice.  When the chips are on the table, I think that tome with the book of shadows and standard familiars is superior to chain, and special familiars.  I have the ability to learn rituals from /all/ classes.  I still get a familiar.  I get three cantrips from any class and this opens a lot of possibilities.

Generally speaking, I do not think I'd spend a feat to get rituals, I'd probably take my ASI or a different feat first.  Chain causes you to sacrifice too much just to get one of the special familiars.  That doesn't mean chain is a poor choice, I just think it's not as good of a choice mechanically speaking.

Thanks for the feedback.  I'm looking at first level spells that are both available to Bard or Wizard, so I can easily just pick Wizard and get what I need.  

I did notice the Tome does essentially tie up your Invocations (assuming Agonizing Blast is already selected).  Chainlocks can face the same issue with Voice and the Gift invocations, but I'm enjoying Mask of Many Faces too much to throw it away for now.  My thought is that with an 18 CHA out the gate I could wait for the ASI, and taking Ritual Caster also removes temptation to multiclass (stats do not afford a Paladin dip, and the character's flavor does not translate to being near the front line).  

We do have a Wizard in the group, but he is played as an abjuration specialist and I'm not seeing the wizard being a huge utility caster.  Out group consists of a Fighter, Cleric, Monk, the Wizard, and my Warlock.  I'm envisioning taking an imp and using the familiar's scouting to offset our lack of a rogue, and on key skills the imp can do a Help action.  And my DM has dangled that while the imp does not come with the variant Magic Resistance, it could be possible with roleplay down the road.  That would absolutely make Chainlock scale at the higher levels.  

I've had great fun as a Hexblade Tome-pact with Find Familiar (owl), and I recommend trying this build.

Fiend warlocks benefit a bit less from the Chainlock/RC flip than Celestial warlocks do.  A Celestial warlock gets two bonus cantrips already, neither of them useless (though anyone who thinks Sacred Flame is a replacement for Eldritch Blast is out of their mind), and Gift of the Ever-Living Ones means they can self-heal with their Radiance pool much more effectively.  Which, in turn, means they can be more sparing with their own heals and use more of their healing output for the party while staying safe.

Fiendlock has no inherent synergy with Chain that way, but man.  Fiendlock with the imp familiar is on point, and people really, really...really...underestimate the value of a fully sapient familiar with hands and the ability to go invisible indefinitely.  They see the familiar being mostly a nonfactor in combat and decide Chain is for the birds, which really is sad.  Ritual Caster isn't as powerful as Book of Ancient Secrets, just like an owl isn't remotely as powerful as an imp or sprite.

In your case, I'd talk to the Wizard player, ask if he's interested in picking up a lot of rituals for utility or if he'd prefer to be a more active spellblasty wizard.  If the latter, go for it.  A spellblasty wizard would likely really appreciate somebody else picking up the utility slack, and like you said - an invisible imp is a good alternative to a rogue for reconnaissance and information gathering.  If the wizard does intend to pick up utility, I would avoid cramping his style.  That's one of the traditional hallmarks of the wizard class, some wizard players would feel some kinda way about somebody 'stealing' their role.

Sacred flame is mostly useful when something gets in my face in melee, or if I am struggling to hit with AC attacks.  As a celestial lock, I very rarely find myself healing /me/ so gift of the ever living ones is kind of meh.  Now, for a blade lock that's likely farther forward and taking hits more often, I can definitely see GotELO being most excellent.

Makes me wonder, what are some useful magic items for a Warlock to have to heal themselves which would shine with CoTELO?

There's also a question of how far down the road are you looking? BoAS gets some pretty spiffy spells as rituals that warlocks otherwise can't get, unless they choose the specific ritual caster class in question. Examples might include Drawmij's instant summons or forbiddance. So it really depends on if you're playing a close-to-pure caster role or the more utilitarian role a Chainlock plays. Chainlocks do have some great Invocations later on, too. Depends on the party makeup and what you want to play. I'm not denigrating either choice, just noting some differences in later levels.

Quote from Halavor_TheWeird >>

There's also a question of how far down the road are you looking? BoAS gets some pretty spiffy spells as rituals that warlocks otherwise can't get, unless they choose the specific ritual caster class in question. Examples might include Drawmij's instant summons or forbiddance. So it really depends on if you're playing a close-to-pure caster role or the more utilitarian role a Chainlock plays. Chainlocks do have some great Invocations later on, too. Depends on the party makeup and what you want to play. I'm not denigrating either choice, just noting some differences in later levels.

 If the higher level rituals are my endgame, I'm likely to wait on Ritual Caster Feat.  I'll get enough bang for the buck with the ASI at 4th level and could look later on.  The character is currently blasting away but I can see him covering the lack of our group having a rogue as a Chainlock, and some ritual casting could be nice in that regard, but not critical.  I just see a good share of Tomelocks scooping Find Familiar to kinda do a little of what a Pact of the Chain does, but I didn't see any thought of the Chainlock using a Feat to gain ritual casting.  

Quote from socon67 >>

Quote from Halavor_TheWeird >>

There's also a question of how far down the road are you looking? BoAS gets some pretty spiffy spells as rituals that warlocks otherwise can't get, unless they choose the specific ritual caster class in question. Examples might include Drawmij's instant summons or forbiddance. So it really depends on if you're playing a close-to-pure caster role or the more utilitarian role a Chainlock plays. Chainlocks do have some great Invocations later on, too. Depends on the party makeup and what you want to play. I'm not denigrating either choice, just noting some differences in later levels.

 If the higher level rituals are my endgame, I'm likely to wait on Ritual Caster Feat.  I'll get enough bang for the buck with the ASI at 4th level and could look later on.  The character is currently blasting away but I can see him covering the lack of our group having a rogue as a Chainlock, and some ritual casting could be nice in that regard, but not critical.  I just see a good share of Tomelocks scooping Find Familiar to kinda do a little of what a Pact of the Chain does, but I didn't see any thought of the Chainlock using a Feat to gain ritual casting.  

Totally get it. Chainlocks with Ritual caster aren't quite as casterish as Tomelocks but damn, you'll get some nice spread-it-around buffing ability with bard or a broad range of stuff with wizard. So my next question: what's your secondary ability score? If you've got the INT, snag wizard. If not, bard might be a good choice. Cleric is also good if you need a backup healer. 

 

Totally get it. Chainlocks with Ritual caster aren't quite as casterish as Tomelocks but damn, you'll get some nice spread-it-around buffing ability with bard or a broad range of stuff with wizard. So my next question: what's your secondary ability score? If you've got the INT, snag wizard. If not, bard might be a good choice. Cleric is also good if you need a backup healer. 

 Stat run is STR-10, INT-13, WIS-12, DEX-14, CON-16, CHA-18.  I was considering going ritual caster feat to not need to multi-class.  Because other than the spell potential it isn't going to add much to the character (specifically the flavor of what I'm going for).

I’m gong to throw another option out there to make it even harder for you. Go with Pact of the Chain and pick up Magic Initiate for 2 cantrips and a 1st level spell. If you go Bard, Faerie Fire or Healing Word are both great 1st level spells and if you go wizard Alarm, Floating Disk, or Shield are all great 1st level spells that stay useful at higher levels. 

Quote from Tim >>

I’m gong to throw another option out there to make it even harder for you. Go with Pact of the Chain and pick up Magic Initiate for 2 cantrips and a 1st level spell. If you go Bard, Faerie Fire or Healing Word are both great 1st level spells and if you go wizard Alarm, Floating Disk, or Shield are all great 1st level spells that stay useful at higher levels. 

 My only thought with trying this is that I feel I'd be better served taking the CHA boost at level 4, and then dipping Bard after that to get the full suite of spells.  

That’s an option, but it’s a trade off. You give some things up too. I prefer going the feat route in order to get the higher level spells and abilities.